A long time ago (20 years ago actually) I’ve received from my father a camera system (that he was using as an amateur photographer) that included the lovely Zenit-E SLR and the Jupiter 37A lens. I’ve kept this lens in a forgotten box for the last 10 years or so, occasionally finding and playing with it for a few minutes. After that it was again in its box…
But today, I’ve found it again and…
I was convinced that a lens with such good photo reviews should also be good for astrophotography. My specimen was build in 1984, as the serial on the lens ring indicates. So it is about 34 years old, almost as old as I am…pretty cool 🙂
Now, for the test: the main reason for choosing this lens for this session was to have a wider field of view on some deep-sky objects in H-alpha light. The nominal 135mm focal length is perfect for the job, when combined with the small pixels of the ASI 1600MM camera. But to focus the system, I’ve first pointed at the Moon. The result is spectacular I might say, with lots of identifiable craters detectable in the image. Very sharp image, and this with the lens wide-open at F/3.5! Indeed, it was done through the H-alpha filter, so not much optical aberrations would have been detected, but this also means that the lens is very well corrected in the red part of the spectrum. And this is from a lens of just 38.5 mm in diameter!
With such good resolution, the next target was chosen: the North America-Pelican nebulae. Only five frames (each a 10 minutes exposure) for this one for now, but it will definitely be my subject for the next clear nights:
And another short test, just to see “what’s out there”, in an area that includes the Omega and Eagle nebulae. Only 4x120sec shots and 1 dark were acquired. The Moon was also pretty close by, and the area was already rather close to the horizon; still a lot of fainter hydrogen signatures can be seen in the background:
And the last shot, Saturn next to the Lagoon and Trifid nebulae, setting behind a tree. Only one shot of just 60 seconds. This gathering is my prime target for the next session…
The conclusion for now is that this lovely small lens is pretty good for astrophotography, at least in H-alpha light. It does however show some coma towards the margins with the ASI 1600MM camera, but this is visible with the lens wide open. Perhaps at a different F-stop it will be better. The next session will show just how good the lens can be…
And a shot of the setup: the Jupiter 37A and ASI1600MM (in the foreground), and the guiding scope (a 50mm finder with ASI 174MM camera):